GraphQL uploads break with certain files

[jamesedmonston]

Description

Hey, I've noticed an issue where certain files types – we're trying .docx, .xls, .xlsx – fail to upload when creating them via a save_*_Asset mutation.

The issue appears to be related to the regex here not validating when the type has periods.

I copied the regex and ran some tests:

application/thisworks validates correctly:

application/this.doesnt.work doesn't validate:

I'm not sure whether simply tweaking the regex will fix it, as I'm unsure how many file extensions FileHelper::getExtensionByMimeType handles.

Steps to reproduce

1. Try to create an asset via a save_*_Asset mutation, with a base64 encoded string that contains periods in the data section, e.g. data:application/vnd.ms-excel;base64,....

Additional info

• Craft version: 3.5.17
• PHP version: 7.3.23
• Database driver & version: MySQL 5.5.5
• Plugins & versions: -

[brandonkelly]

Craft 3.5.18 is out now with a fix for this. Thanks for reporting!